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authorJan Höppner <hoeppner@linux.ibm.com>2020-09-14 13:56:47 +0200
committerJens Axboe <axboe@kernel.dk>2020-09-14 19:40:21 -0600
commit709192d531e5b0a91f20aa14abfe2fc27ddd47af (patch)
tree3ef738f7fb01ff7d1a9630bcb748710733bfb2c5 /drivers/s390/block
parentfd04358e0196fe3b7b44c69b755c7fc329360829 (diff)
s390/dasd: Fix zero write for FBA devices
A discard request that writes zeros using the global kernel internal ZERO_PAGE will fail for machines with more than 2GB of memory due to the location of the ZERO_PAGE. Fix this by using a driver owned global zero page allocated with GFP_DMA flag set. Fixes: 28b841b3a7cb ("s390/dasd: Add discard support for FBA devices") Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/s390/block')
-rw-r--r--drivers/s390/block/dasd_fba.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index cbb770824226..1a44e321b54e 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -40,6 +40,7 @@
MODULE_LICENSE("GPL");
static struct dasd_discipline dasd_fba_discipline;
+static void *dasd_fba_zero_page;
struct dasd_fba_private {
struct dasd_fba_characteristics rdc_data;
@@ -270,7 +271,7 @@ static void ccw_write_zero(struct ccw1 *ccw, int count)
ccw->cmd_code = DASD_FBA_CCW_WRITE;
ccw->flags |= CCW_FLAG_SLI;
ccw->count = count;
- ccw->cda = (__u32) (addr_t) page_to_phys(ZERO_PAGE(0));
+ ccw->cda = (__u32) (addr_t) dasd_fba_zero_page;
}
/*
@@ -830,6 +831,11 @@ dasd_fba_init(void)
int ret;
ASCEBC(dasd_fba_discipline.ebcname, 4);
+
+ dasd_fba_zero_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+ if (!dasd_fba_zero_page)
+ return -ENOMEM;
+
ret = ccw_driver_register(&dasd_fba_driver);
if (!ret)
wait_for_device_probe();
@@ -841,6 +847,7 @@ static void __exit
dasd_fba_cleanup(void)
{
ccw_driver_unregister(&dasd_fba_driver);
+ free_page((unsigned long)dasd_fba_zero_page);
}
module_init(dasd_fba_init);